Realization of high-quality HfO2 on In0.53Ga0.47As by <i>in-situ</i> atomic-layer-deposition

Abstract

High κ dielectric of HfAlO/HfO2 was an in-situ atomic-layer-deposited directly on molecular beam epitaxy grown In0.53Ga0.47As surface without using pre-treatments or interfacial passivation layers, where HfAlO (HfO2:Al2O3 ∼ 4:1) with high re-crystallization temperature was employed as the top oxide layer. The HfAlO (∼4.5 nm)/HfO2 (0.8 nm)/In0.53Ga0.47As metal oxide semiconductor capacitors have exhibited an oxide/In0.53Ga0.47As interface free of arsenic-related defective bonding, thermodynamic stability at 800 °C, and low leakage current densities of &amp;lt;10−7 A/cm2 at ±1 MV/cm. The interfacial trap density (Dit) spectra in absence of mid-gap peaks were obtained by temperature-dependent capacitance and conductance with Dit’s of 2–3 × 1012 eV−1 cm−2 below and 6–12 × 1011 eV−1 cm−2 above the mid-gap of In0.53Ga0.47As, respectively. An equivalent oxide thickness of less than 1 nm has been achieved by reducing the HfAlO thickness to ∼2.7 nm with the same initial HfO2 thickness of ∼0.8 nm.